1. Field
The present invention relates to micro devices. More particularly embodiments of the present invention relate to micro pick up arrays having compliant contacts.
2. Background Information
Integration and packaging issues are one of the main obstacles for the commercialization of micro devices such as radio frequency (RF) microelectromechanical systems (MEMS) microswitches, light-emitting diode (LED) display systems, and MEMS or quartz-based oscillators.
Traditional technologies for transferring devices include, e.g., “transfer printing”, which involves using a transfer wafer to pick up an array of devices from a donor wafer. The array of devices are then bonded to a receiving wafer before removing the transfer wafer. Some transfer printing process variations have been developed to selectively bond and de-bond a device during the transfer process. In both traditional and variations of the transfer printing technologies, the transfer wafer is de-bonded from a device after bonding the device to the receiving wafer. In addition, the entire transfer wafer with the array of devices is involved in the transfer process.
More recently it has been proposed to transfer a semiconductor die from a host substrate to a target substrate using elastomeric stamps in which a stamp surface adheres to a semiconductor die surface via van der Waals forces.